Comparative form of coarse: more coarse(adjective)
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Use "coarser" in a sentence
"We call the coarser level a person’s “not being substantially existent in the sense of being self-sufficient” and the subtler level a person’s “not being inherently existent.”"
"Use cornmeal imported from Italy, not because the corn is necessarily better but because the grind is coarser, which is best suited to polenta."
"The greater the current to be carried, the coarser is the wire required for safety."